Keyboard



June 4, 1935. H. LUEDTKE 2,003,894

KEYBOARD Filed June 8, 1935 Patented June 4, 1935 UNITED STATES PATENT OFFICE Application June 8, 1933, Serial No. 674,957 In Germany June 8, 1932 11 Claims.

The present invention relates to a keyboard system and more particularly to a keyboard which is combined with electrical contacts or relays and which is not alone adapted for use in connection with normal musical instruments, such as for instance organs, fortepianos or orchestrion-like instruments, but also as a register keyboard for the works of organs and the like. The novel keyboard may further be used for recording sound on sound films by means of a photoelectical cell, for recording sound in the form of note writing, for instance in the form of or substantially in the form of modern orchestra scores. The invention may also be used in combination with typewriters, calculating machines, cash registers, line selectors in telephone exchanges and for operating type printers and other apparatus employed in modern communication systems.

lAccording to the invention the keys can not only as usual be arranged in a horizontal plane but also in a vertical plane or in planes of any desired inclination. The keys are all exactly or substantially of the same shape. Preferably the key heads have the form of honeycombs. When key heads of this form are used the play eld or number of keys in a group may easily be increased in all directions. The eiectexerted by the individual keys may in accordance with the invention be altered by means of an electrical switching device. If for instance an A key, when depressed, at a certain position of the switch will produce a violin tone the same key may be caused to produce for instance a tone having the character of a pianoforte tone simply by changing the position of the switch. The invention also comprises means which makes it possible to change over from one tone system to another.

Some constructional forms of the invention are illustrated by way of examples in the accompanying drawing.

Fig. 1 shows a portion of a keyboard in plan View.

Fig. 2 shows, also in plan view, a portion of a modied form of keyboard.

Fig. 3 is a vertical sectional View showing a key and an electrical contact device operated by the same.

Fig. 4 is a horizontal sectional view taken on line 4-4 in Fig. 3.

Fig. 5 is a sectional view showing the crosssectional form of the key heads.

Fig. B is a lateral plan view showing a key head.

Fig. 7 is a plan view of the same key head.

The portion of a keyboard shown in Fig. 1 consists of I6 keys I which are arranged in such a manner, that a continuous eld is formed. The keys are grouped in four oblique and parallel rows of which each contains four keys. This keyboard is designed for musical purposes. As indicated by legends the individual keys control 5 tones of the common tone or note system which is used over the entire civilized world and according to which the musical tones are grouped in octaves of which each consists of twelve semitones. When comparing the keyboard section 10 shown with the keyboard of a modern pianoforte it will be seen, that the three lower horizontal rows of keys of this section contain all tones of an octave. Some of these tones are represented for a second time in the uppermost row which also contains the first tone of the next octave.

The section of a keyboard shown in Fig. 2 consists of keys which together form a continuous field. The keys are grouped in four oblique and 2o parallel rows of which each contains iive keys. Two keys in the upper right corner of the keyboard section carry no legends. These keys may for instance be used for operating master switches or the like. The individual keys of this keyboard are intended to control the tones of a tone system consisting of eighteen third tones.

The individual keys or groups of keys may of course be grouped in any desired manner and may be arranged for any tone system, for instance for a tone system consisting of series of 24 quarter tones, without the scope of the invention being surpassed. As already mentioned the keyboard arrangement according to the invention may be employed for musical purposes of diierent kinds, for instance for organ registers which are grouped in manuals, and for a great variety of recording, reproducing, registering and controlling purposes.

A preferred embodiment of the novel keyboard, which is adapted for use in combination with all today imaginable musical instruments and in which, therefore, each section or unit covers an octave, has a, front row consisting of four keys which are arranged adjacent each other. The other keys are arranged behind this front row in honeycomb-like relation. Keyboards used for other purposes, for instance keyboards used in connection with the registers or organs or calculating machines, may of course be otherwise arranged and the front row of each unit may for instance consist of five or seven keys. On account of the honeycomb-like arrangement of the key heads the fingers may be passed from one key to another Without lifting them from the keyboard.

Accords, double strokes and the like with constant interval distances may therefore be performed glissando i. e. slidingly, without altering the fingering.

It will be evident, that the fingering must be changed, on passing over from one octave section to another, if the second section is lying to the right or left of the rst section. It is however also within the scope of the invention to arrange a second section. also behind the rst one. Groups of keys or keyboard sections may be added to the existing in all directions. It is in other words possible to build up a play eld of almost infinite dimensions.

In such cases a plurality of keys of the same significance or character must be present in each unit. For instance in keyboards for musical Ypurposes each tone of the scale must berepresented by a plurality of keys. Keyboards of this kind may be arranged without difficulties since the keys according to the invention cooperate directly with electrical contacts and relays, so that no -lever mechanisms or the like are involved and thev travel or stroke of the keys is much shorter than at the operating mechanism of the normal musical instruments.

f -According to the invention means are provided which makes it possible to alter the effect exerted by the key and for instance during the playing key head l and a shank part 6.

to 'switch over from a `tone system consisting 'of series of Vtwelve semitones to a system consisting of series of eighteen third tones or from a 16' to an 8 or to a 4 organ tone and the like. These means :comprise master switches adapted to in- -uence'all unit sections (octave sections, organ manuals or the like) of the keyboard. A single master switch may be used for influencing one, several or Aall lsections or each section-may be equipped with aplurality of master switches. By v-means of these switches each individual key may be caused to make contact withA a great variety ofdiiferent contacts and consequently to create Vdifferent sound effects.

In fortepianos and thelike when a key is depressed'themovement is transmitted by means -of complicated lever mechanisms. Incontrast hereto the keys according to the invention act `directly upon the electrical contacts in the direction in which they are depressed without'the .use of any intermediate mechanical devices.

The key shown in Figs. 3 and 4 consists of a The shank part 6 is'locatedin asleeve l, which again is fixed ina :support plate 8. VThe shank is equipped with a projecting pin 9 adapted to slide in a groove lil in the sleeve 'i and near the lower end of the shank a stop ring is xed which limits the upward movement-of the key. 2 and 2' denote two cooperating contact members. When the key is depressed against the forceof the spring 3 the pin 9 will press contact member 2 against contact 2, whereby a circuit is closed.

Fig. 5 is across-sectional view of the keyboard shown in Fig. l. As will be seen the surface of the key headslying behind each other are curved in such-a manner, that the fingers easily may slide from one row of keys onto the next.

As will'be seen from Fig. 6 (and also from Fig. .5) the surface of each key head consists of two finger Contact faces 4 and 5, which form a flat angle with each other. When the surface of the key heads is formed `in this mannerone or more fingers may always be moved slidingly i. e. glissando from one key to the next.

Fig. r7 showsthe relation between both nger claims.

contact faces of a key head. The foremost and larger part at is of curved shape'and the part 5 consists of a depression or groove the edges of which preferably are parallel or substantially parallel to the base of the key head.

'I'he invention is not only suited for use in combination with manually operated keyboards. Similar arrangements may with the same advantage be used as pedal keyboards, i. e. .instead of the usual organ pedals. Also inthis case the front of each octave section consists of four keys and the dimensions of a pedal may be reduced to such a degree, that the total area of a pedal with anormal number of keys is only thehalf of the area of the organ pedals hitherto known. A pedal area which hitherto was played with two feet `can therefore now'be operated with a single foot.

Moreover, when organ pedals are arranged in accordance with the present invention also chords such as for instance thirds may be made, and tones which l.are `separated iby .so .large an interval, that they'can notibe played legatoiwhen normal pedals are used, .can now be played absolutely legato. l

Various modifications may fbe made in the invention without departing from 'the spirit Vthereof or the scope of the 'claimsand thereforethe exact forms shown .are -to be taken as illustrative only and not in alimiting sense, and I desire therefore, that ronly .suchlimitations shall bei Aplaced thereon as are imposed by the prior .art or are specically set forth `in the appended 1. A keyboard `comprising :keys with .substantially uniformly shaped-hexagonal key heads in honeycomb-like formation arranged in a single general plane adjacent each other and in .close relation, thereby forming a continuous I eld, adapted to be `extended yafter .desirein 'all ,directions and to 'be subdivided `in any desired 'manner, the surface fof each key head being inclined towards its ledges 4so as to` securea 'smooth Apassagefrom each `key head to the 'surrounding ones.

`2. A keyboard Vcomprising keys with substantially uniformly shaped hexagonal key heads in honeycomb-like formation arranged vin a vsingle Vhorizontal plane adjacent l.eachother 'and in close relation, thereby formingia .continuousield'adapted'to be extended after desire in all vdirections and to'be subdivided in Aany desired manner, .the surface of each key head being 'inclined towards 'its edges so as to secure-a smooth passage from each key head to the-surrounding ones.

3. A keyboard Vcomprising'keys with substantially uniformly shaped hexagonalkey heads in honeycomb-'like formation arranged vin a .single vertical plane .adjacent each other and in close relation, thereby forming a continuous field adapted to `be extended after desirein alldirections and tobe subdivided in any desired manner, Vthe surface of each keyhead being inclined towards its edges so as to secure a smooth ypasso as to secure a smooth passage from each key head to the surrounding ones.

5. A keyboard comprising keys with substantially uniformly shaped hexagonal key heads arranged adjacent each other in close relation, some of the keys being adapted, when operated, to alter the effect exerted by the other keys, the surface of each key head being inclined towards its edges so as to secure a smooth passage from each key head to the surrounding ones.

6. A keyboard for musical purposes comprising keys with practically uniformly shaped heX- agonal key heads in honeycomb-like formation arranged in a single general plane in close relation, thereby forming a continuous field consisting of sections of keys covering an octave, the front of each section being formed by a row of four keys, the surface of each key head being inclined towards its edges so as to secure a smooth passage from each key head to the surrounding ones.

7. A keyboard for musical purposes comprising keys with practically uniformly shaped hexagonal key heads in honeycomb-like formation arranged in a single plane in close relation, thereby forming a continuous field consisting of units of keys covering a definite range of tones, certain tones being represented more than once in each unit, the surface of each key head being inclined towards its edges so as to secure a smooth passage from each key head to the surrounding ones and allow a glissando playing and unaltered fingerings when the fingers are moved over the keys.

8. A keyboard for musical purposes comprising keys with practically uniformly shaped hexagonal key heads in honeycomb-like formation arranged in a single plane in close relation, thereby forming a continuous field consisting of units of keys covering a definite range of tones, the surface of each key head consisting of two finger contact faces forming a fiat angle with each other and allowing a glissando movement of the fingers from key to key.

9. A keyboard for musical purposes comprising keys with practically uniformly shaped hexagonal key heads in honeycomb-like formation arranged in a single plane in close relation, thereby forming a continuous eld consisting of units of keys covering a definite range of tones, the surface of each key head consisting of two finger Contact faces, the foremost face being larger and of curved shape, the other face consisting of a circular depression the edge of which is lying in a plane substantially parallel with the plane through the edges of the basey of the key head.

10. A keyboard for musical purposes comprising keys with hexagonal key heads in honeycomblike formation arranged in a single plane in close relation, thereby forming a continuous field consisting of units of keys covering a definite range of tones, the surface of each key head consisting of two finger contact faces forming a fiat angle with each other and allowing a glissando movement of the fingers from key to key, some of the keys being adapted, when operated, to alter the effect exerted by the other keys.

1l. A keyboard particularly for organ pedals and the like, comprising keys with practically uniformly shaped hexagonal key heads arranged in a single general plane in close relation, thereby forming a continuous field, said keys being dimensioned so as to allow the entire field to be operated by a single foot and the heads of the keys being so arranged and formed, that Widely separated tones may be played legato.

HANS LUEDTKE. 

